Relay module

Abstract

The disclosure relates to an electromagnetic relay module, comprising a first circuit branch comprising a first capacitor and a first relay connected in series with the first capacitor, a second circuit branch comprising a second capacitor and a second relay connected in series with the second capacitor, a switching element which is arranged between the first circuit branch and the second circuit branch and comprises a first switching state and a second switching state. In the first switching state of the switching element the first circuit branch and the second circuit branch are arranged in a parallel connection. In the second switching state of the switching element the first relay and the second relay are arranged in a series connection. The switching element is configured to change from the first switching state to the second switching state in the switch-on process of the relay module

What is claimed is: 
     
         1 . An electromagnetic relay module, comprising:
 a first circuit branch comprising a first capacitor and a first relay connected in series with the first capacitor,   a second circuit branch comprising a second capacitor and a second relay connected in series with the second capacitor,   a switching element which is arranged between the first circuit branch and the second circuit branch and comprises a first switching state and a second switching state,   wherein in the first switching state of the switching element the first circuit branch and the second circuit branch are arranged in a parallel connection, and wherein in the second switching state of the switching element the first relay and the second relay are arranged in a series connection, and   wherein the switching element is configured to change from the first switching state to the second switching state in the switch-on process of the electromagnetic relay module.   
     
     
         2 . The electromagnetic relay module of  claim 1 , wherein the electromagnetic relay module comprises a holding position in which a first armature is attracted by the first relay and in which a second armature is attracted by the second relay, and wherein the switching element is configured to change from the first switching state to the second switching state as soon as the electromagnetic relay module has taken a stop position. 
     
     
         3 . The electromagnetic relay module of  claim 2 , wherein the first capacitor is configured to provide a first charging current to the first relay in the first switching state of the switching element, and the second capacitor is configured to provide a second charging current to the second relay in the first switching state of the switching element, the first charging current being suitable for causing an attraction and holding of the first armature, and wherein the second charging current is suitable to cause an attraction and holding of the second armature. 
     
     
         4 . The electromagnetic relay module of  claim 3 , wherein the electromagnetic relay module is connected to a voltage source which is configured to provide a constant voltage, wherein the first circuit branch and the second circuit branch is connected to the voltage source. 
     
     
         5 . The electromagnetic relay module  claim 4 , wherein the first capacitor provides the first charging current and the second capacitor provides the second charging current, when the constant voltage is applied to the first circuit branch and to the second circuit branch. 
     
     
         6 . The electromagnetic relay module of  claim 1 , wherein the first switching state of the switching element comprises a higher resistance of the switching element compared to a resistance of the switching element in the second switching state and wherein the second switching state of the switching element comprises a lower resistance of the switching element compared to a resistance of the switching element in the first switching state. 
     
     
         7 . The electromagnetic relay module of  claim 6 , wherein the switching element comprises a diode, wherein the diode is configured to transition from the first switching state to the second switching state upon reaching a forward voltage of the diode. 
     
     
         8 . The electromagnetic relay module of  claim 7 , wherein the switching element comprises a second diode, a series resistor, or a combination thereof. 
     
     
         9 . The electromagnetic relay module of  claim 6 , wherein the switching element comprises a transistor, and wherein the transistor comprises a bipolar transistor or a metal-oxide-silicon field-effect transistor (MOSFET). 
     
     
         10 . The electromagnetic relay module of  claim 9 , wherein the transistor is preceded by an RC element and a voltage divider, by which a time constant is defined. 
     
     
         11 . The electromagnetic relay module of  claim 9 , wherein the transistor is preceded by a controller which is configured to determine a switching time of the transistor as a function of a measured current in the first circuit branch or the second circuit branch. 
     
     
         12 . The electromagnetic relay module of  claim 11 , wherein the controller is configured to provide a switching voltage for switching the switching element when the measured current falls below a predetermined limit value. 
     
     
         13 . The electromagnetic relay module of  claim 12 , wherein a first blocking diode is arranged between the first relay and the switching element to block a flow of current from the switching element to the first relay and a second blocking diode is arranged between the second relay and the switching element to block a flow of current from the second relay to the switching element. 
     
     
         14 . The electromagnetic relay module of  claim 1 , wherein the electromagnetic relay module is a safety relay module configured to fulfill a safety-relevant function and wherein the first relay and the second relay are redundant relays. 
     
     
         15 . The electromagnetic relay module of  claims 1 , wherein the electromagnetic relay module is included in an emergency stop switch or a protective door switch or a magnetic switch or with a light curtain. 
     
     
         16 . The electromagnetic relay module of  claim 11 , wherein the controller comprises a microcontroller. 
     
     
         17 . The electromagnetic relay module of  claim 1 , wherein the electromagnetic relay module comprises a holding position in which an armature is attracted by the first relay, wherein the switching element is configured to change from the first switching state to the second switching state as soon as the electromagnetic relay module has taken a stop position. 
     
     
         18 . The electromagnetic relay module of  claim 17 , wherein the first capacitor is configured to provide a charging current to the first relay in the first switching state of the switching element, the charging current being suitable for causing an attraction and holding of the armature. 
     
     
         19 . The electromagnetic relay module of  claim 1 , wherein the electromagnetic relay module comprises a holding position in which an armature is attracted by the second relay, wherein the switching element is configured to change from the first switching state to the second switching state as soon as the electromagnetic relay module has taken a stop position. 
     
     
         20 . The electromagnetic relay module of  claim 19 , wherein the second capacitor is configured to provide a charging current to the second relay in the first switching state of the switching element, the charging current suitable to cause an attraction and holding of the armature.